1. Field of the Invention
The invention relates generally to a process for preparing biomass particles suitable for use in fast pyrolysis reaction systems, such as entrained flow, fluidized bed, ablative, vacuum, and cyclonic conversion reactors, and more particularly to a mild thermal pretreatment process for making biomass material more susceptible to mechanical particle size reduction processes.
2. Description of the Related Art
Prior art processes for reducing the particle size of biomass materials include methods such as milling, grinding, shredding, and the like. Because of the fibrous and resilient nature of many biomass materials, these processes require relatively large amounts of energy, and tend to result in fiber-like or needle-like particles.
Processes have been suggested for converting biomass material to gaseous or liquid products, in particular fuel products. The more promising of these processes comprise entrainment flow reactors or fluidized bed reactors. In general, the optimum particle shape for reactors of this type is a spherical shape.
Thus, there is a particular need for processes for reducing the particle size of solid biomass materials requiring less energy than prior art processes. There is a further need for such processes providing biomass particles having a more spherical shape than the processes known in the art.